Optical design studies will be carried out to devise an optics module for flow cytometry such that the flow chamber becomes integral part of the optical system, and that fluorescence will be collected for almost a full 4Pi steridians, (dual-hemispherical space). An improvement of at least a factor of four in the efficiency of light collection over existing designs, and by more than an order of magnitude over that offered by other flow cytometers seems attainable. Optimized, and customized optics design has not been incorporated into any of the high performance commercial flow cytometers. The proposed optics module would increase sensitivity and precision of such instruments to where measurement of multiple tagged cells, and possibly of gene products might become feasible. The feasibility of high resolution imaging by such optimized optics will also be examined. Such optimized design would bring state of the art optics to flow cytometry.